Method of forming dielectric films, new precursors and their use in semiconductor manufacturing

ABSTRACT

Method of deposition on a substrate, of a metal containing dielectric film comprising a compound of the formula (I):
 
(M 1   1-a M 2   a )O b N c ,  (I)
 
wherein 0≦a&lt;1, 0&lt;b≦3, 0≦c≦1, M 1  represents a metal selected from (Hf), (Zr) and (Ti); and M 2  represents a metal atom atoms, which comprises the following steps:
         A step a) of providing a substrate into a reaction chamber;   A step (b) of vaporizing a M 1  metal containing precursor of the formula (II):
 
(R 1   y Op) x (R 2   t Cp) z M 1 R′ 4-x-z   (II)
 
wherein 0≦x≦3, preferably x=0 or 1, 0≦z≦3, preferably z=1 or 2, 1≦(x+z)≦4, 0≦y≦7, preferably y=2 0≦t≦5, preferably t=1, (R 1   y Op) represents a pentadienyl ligand, which is either unsubstituted or substituted; (R 2   t Cp) represents a cyclopentadienyl (Cp) ligand, which is either unsubstituted or substituted, to form a first gas phase metal source;
   A step c) of introducing the first gas phase metal source in the reaction chamber, in order to provoke their contact with said substrate, to generate the deposition of a metal containing dielectric film comprising a compound of the formula (I) as hereinbefore defined, on said substrate. Compound the formula (II 1 ):
 
(R 2   t Cp)M 1 [N(R 39 )(R 40 )] 3   (II 1 )
 
corresponding to the formula (II) as hereinabove defined in Claim  1 , wherein x=0, z=1 and R′ represents the group N(R 39 )(R 40 ).

This application is a 371 of International PCT ApplicationPCT/EP2007/052507, filed Mar. 16, 2007, which claims priority toPCT/EP06/062893 filed Jun. 2, 2006, the entire contents of which areincorporated herein by reference.

The invention relates to a method of forming high-k dielectric filmssuch as hafnium or zirconium oxides or oxynitrides and their use formanufacturing semi-conductors.

With the shrink of the critical dimensions of the future generation ofsemi-conductor devices, the introduction of new materials, especiallyhaving high dielectric constant, is required. In CMOS architectures,high-k dielectrics are required to replace SiO₂ which reaches itsphysical limits, having typically a SiO₂ equivalent thickness of about 1nm.

Similarly, high-k dielectrics are required in Metal-Insulator-Metalarchitectures for RAM applications. Various metal compositions have beenconsidered to fulfill both the materials requirements (dielectricconstant, leakage current, crystallization temperature, charge trapping)and the integration requirements (thermal stability at the interface,dry etching feasibility . . . ).

The Group IV based materials, such as HfO₂, HfSiO₄, ZrO₂, ZrSiO₄,HfZrO₄, HfLnO_(x) (Ln being selected from the group comprising scandium,yttrium and rare-earth elements) and more generally HfMOx and ZrMOx, Mbeing an element selected from Group II, Group IIIa and Group IIIb, or atransition metal, are among most promising materials. Furthermore, GroupIV metals composition can also be considered for electrode and/or Cudiffusion barrier applications, such as TiN for mid-gap metal gate andHfN, ZrN, HfSi, ZrSi, HfSiN, ZrSiN, TiSiN for MIM electrodes.

The main industrial options to enable the deposition of such thin filmswith a reasonable throughput and an acceptable purity are vapor phasedeposition techniques, such as MOCVD (Metal-organic Chemical VaporDeposition) or ALD (Atomic Layer Deposition). Such deposition processesrequire metal precursors that must fulfill drastic requirements for aproper industrial use. Metal-organic or metal-halide precursors arerequired for those processes. Various hafnium and zirconiummetal-organic compounds have been considered as precursors to enablesuch a deposition.

Halides such as HfCl₄, ZrCl₄ are the most common Hf/Zr precursors andhave been widely described. Kim et al. disclosed the use of HfCl₄ forthe deposition of HfO₂ by ALD (Kim et al., Electrochem Soc Proceedings2005-05, 397, 2005). However, some by-products generated during thedeposition process, such as HCl or Cl₂, can cause surface/interfaceroughness that can be detrimental to the final properties. Otherpossible byproducts, depending on the oxygen source used, may behazardous. For instance, OCl₂, through the OCl fragment by QMS, has beendetected as a byproduct of the reaction between HfCl₄ and O₃. Moreover,in the case of high-k oxide, Cl or F impurities are highly detrimentalto the final electrical properties.

Triyoso et al. and Chang et al. studied the use of Hf(OtBu)₄ for HfO₂MOCVD and ALD, respectively [Triyoso et al.; J. Electrochem. Soc.,152(3), G203-G209 (2005); Chang et al.; Electrochem. Solid. State Let.,7(6), F42-F44 (2004)]. Williams et al. have evaluated Hf(mmp)₄ andHf(OtBu)₂(mmp)₂ for MOCVD of HfO₂. In WO2003035926, Jones et al.disclose solid Ti, Hf. Zr and La precursors improved with donorfunctionalized alkoxy ligand (1-methoxy-2-methyl-2-propanolate[OCMe₂CH₂OMe, mmp]) which helps inhibiting oligomerization of Zr and Hfalkoxide compounds and increasing their stability towards moisture.However, all those alkoxide precursors have the drawback not to enableself-limited deposition in ALD process as suggested by Potter et al. (R.J. Potter, P. R. Chalker, T. D. Manning, H. C. Aspinall, Y. F. Loo, A.C. Jones, L. M. Smith, G. W. Critchlow, M. Schumacher, Chem. Vap.Deposition, 2005, 11, N^(o) 3, 159-167).

Alkylamides precursors such as Hf(NEtMe)₄, Hf(NMe₂)₄, Hf(NEt₂)₄ havebeen widely disclosed in the literature [Senzaki et al, J. Vac. Sci.Technol. A 22(4) July/August 2004; Haussmann et al, Chem. Mater. 2002,14, 4350-4353; Kawahara et al., J. Appl. Phys., Vol 43, N^(o) 7A, 2004,pp 4129-4134; Hideaki et al., JP 2002-093804; Metzner et al. U.S. Pat.No. 6,858,547; Dip et al. US 2005/0056219 A1]. Group IV alkylamides areboth suitable for ALD and MOCVD processes. Furthermore, some are liquidat room temperature (Hf(NEt₂)₄ and Hf(NEtMe)₄) and of sufficientvolatility, and they allow self-limited ALD at low temperature for alimited thermal budget process. However, Group IV alkylamides,alkylamides in particular Zr compounds, have several drawbacks, amongwhich they may decompose during the distribution to some extent leadingto a possible clogging of the feeding line or the vaporizer, they maygenerate particles during deposition, they may entail non-uniformcompositions during deep trenches deposition processes, and they onlyallow a narrow self-limited ALD temperature window, hence reducing theprocess window. In particular, Zr(NEtMe)₄ may decompose in thedistribution lines and generate particles above 170° C. which is acommon distribution temperature. Hf(NEtMe)₄ is more thermally stable yetdo not afford self-limited atomic layer deposition above 300° C. due tothermal decomposition.

In WO 2007/055088, Thenappan et al. disclose hafnium and zirconiumguanidinates complexes and their application for vapor phase deposition.Hf(NEt₂)₂[(NiPr—CNEt₂]₂ is given as example. Hafnium and zirconiumguanidinates are however generally solids with a very limitedvolatility. As exemplified in thermal gravimetric analysis, one may notobtain Hf(NEt₂)₂[(NiPr—CNEt₂]₂ in vapour phase, without a risk ofthermal decomposition and a subsequent particle generation.

Lehn et al. (Chem. Vap. Deposition, 2006, 12, 280-284) disclosetetrakis(trimethylhydrazido) zirconium [Zr(NMeNMe₂)₄,] and hafnium andtheir use for low temperature CVD. The exemplified compounds have anacceptable volatility (sublimation at 0.06 Torr, 90° C. reported) butthey are solid at room temperature.

Carta et al. disclose the use of bis(cyclopentadienyl)bisdimethylhafnium, [HfCp₂Me₂] (Carta et al. discloses in Electrochem SocProceedings, 260, 2005-09, 2005) and several authors (Codato et al.,Chem Vapor Deposition, 159, 5, 1995; Putkonen et al., J Mater Chem,3141, 11, 2001; Niinisto et al., Langmuir, 7321, 21, 2005) proposed anew family of Zr and Hf compounds as alternatives to hafnium andzirconium alkylamides: Bis(cyclopentadienyl)bisdimethyl hafnium,bis(cyclopentadienyl)bisdimethyl zirconium, which allow an efficient ALDdeposition process with an ALD window up to 400° C. and an achievementof films with less than 0.2% C in optimized conditions with H₂O asco-reactant. However, HfCp₂Me₂ and ZrCp₂Me₂ both have the drawback ofbeing solid products at room temperature (HfCp₂Me₂ melting point is57.5° C.). This prevents IC makers to use those precursors in anindustrial manner, that is using delocalized containers filling, andentail both facilitation and process issues.

In U.S. Pat. No. 6,743,473, Parkhe et al. disclose the use of(Cp(R)_(n))_(x)MH_(y-x), to make a metal and/or a metal nitride layer,where M is selected from tantalum, vanadium, niobium and hafnium, Cp iscyclopentadienyl, R is an organic group. Only examples of tantalum andniobium cyclopentadienyl compounds are disclosed. However, no liquidprecursor or a precursor having a melting point lower than 50° C. isdisclosed.

Liquid bis(cyclopentadienyl) derivatives have recently been proposed byHeys et al. in WO 2006/131751 A1. However, they still present thedisadvantage of limited volatility and also present large sterichindrance that may limit the achieved growth rate.

Today, there is a need for providing liquid or low melting point (<50°C.) group IV precursor compounds, and in particular Hf and Zr compounds,that would allow simultaneously a proper distribution (physical state,thermal stability at distribution temperatures), a wide self-limited ALDwindow, and a deposition of pure films either by ALD or MOCVD.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects for the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like elements are given the same or analogous reference numbersand wherein:

FIG. 1 is a thermal gravimetric analysis (TGA) graph illustrating themass loss versus temperature results for Zr(EtCp)(NMe₂)₃;

FIG. 2 is a TGA graph comparing the mass loss versus temperature resultsfor Zr(EtCp)(NMe₂)₃ to that of Zr(NEtMe)₄;

FIG. 3 is a TGA graph illustrating the mass loss versus temperatureresults for Hf(EtCp)₂Me₂; and

FIG. 4 is an Auger profile of the hafnium oxide film formed byHf(EtCp)₂Me₂ and O₃.

According to the invention, certain cyclopentadienyl or pentadienylbased group IV metal-organic precursors have been found suitable for thedeposition of Group IV metal containing thin films by either ALD orMOCVD processes and to have the following advantages:

-   -   They are liquid at room temperature or having a melting point        lower than 50° C.,    -   They are thermally stable to enable proper distribution (gas        phase or direct liquid injection) without particles generation,    -   They are thermally stable to allow wide self-limited ALD        window, 4) allowing deposition of a variety of Group IV metals        containing films, including ternary or quaternary materials, by        using one or a combination of co-reactants (selected from the        group comprising of H₂, NH₃, O₂, H₂O, O₃, SiH₄, Si₂H₆, Si₃H₈,        TriDMAS, BDMAS, BDEAS, TDEAS, TDMAS, TEMAS, (SiH₃)₃N, (SiH₃)₂O,        TMA or an aluminum-containing precursor, TBTDET, TAT-DMAE, PET,        TBTDEN, PEN, lanthanide-containing precursors such as Ln(tmhd)₃        . . . ).

According to a first embodiment, the invention relates to a method ofdeposition on a substrate, of at least one metal containing dielectricfilm comprising a compound of the formula (I):(M¹ _(1-a)M² _(a))O_(b)N_(c),  (I)wherein:

0≦a≦1,

0≦b≦3, preferably 1.5≦b≦2.5;

0≦c≦1,

M¹ represents a metal selected from hafnium (Hf), zirconium (Zr) andtitanium (Ti); and

M² represents a metal atom selected from magnesium (Mg), calcium (Ca),zinc (Zn), bore (B), aluminum (A), indium (In), silicon (Si), germanium(Ge), tin (Sn), hafnium (Hf), zirconium (Zr), titanium (Ti), vanadium(V), niobium (Nb), tantalum (Ta); and the Lanthanides atoms, moreparticularly scandium (Sc), yttrium (Y) and lanthanum (La) andrare-earth metal atoms, which comprises the following steps:

A step a) of providing a substrate into a reaction chamber;

A step (b) of vaporizing at least one M¹ metal containing precursor ofthe formula (II):(R¹ _(y)Op)_(x)(R² _(t)Cp)_(z)M¹R′_(4-x-z)  (II)wherein:

M¹ is as hereinabove defined;

0≦x≦3, preferably x=0 or 1;

0≦z≦3, preferably z=1 or 2;

1≦(x+z)≦4;

0≦y≦7, preferably y=2 0≦t≦5, preferably t=1;

(R¹ _(y)Op) represents a pentadienyl (Op) ligand, which is eitherunsubstituted or substituted by one or more R¹ groups, y representingthe number of substituting R¹ groups on said pentadienyl ligand;

(R² _(t)Cp) represents a cyclopentadienyl (Cp) ligand, which is eitherunsubstituted or substituted by one or more R² groups, t representingthe number of substituting R¹ groups on said cyclopentadienyl ligand;

R¹ and R², are identical or different and are independently selectedfrom the group consisting of the chloro group, the linear or branched,alkyl groups having from one to four carbon atoms, the N-alkyl aminogroups, wherein the alkyl group is linear or branched and has from oneto four carbon atoms, the N,N-dialkyl amino groups, wherein each alkylgroup, identical or different from the other, is linear or branched andhas from one to four carbon atoms, the linear or branched alkoxy groups,having from one to four carbon atoms, the alkylsilylamides groups, theamidinates groups and the carbonyl group;

R′ represents a ligand independently selected from the group consistingof the hydrogen, fluoro, chloro, bromo or iodo atoms, the linear orbranched, alkyl groups having from one to four carbon atoms, the N-alkylamino groups, wherein the alkyl group is linear or branched and has fromone to four carbon atoms, the N,N-dialkyl amino groups, wherein eachalkyl group, identical or different from the other, is linear orbranched and has from one to four carbon atoms, the linear or branchedalkoxy groups, having from one to four carbon atoms, the alkylsilylamino groups wherein the alkyl group is linear or branched and has fromone to four carbon atoms, the dialkylsilyl amino groups wherein eachalkyl group, identical or different from the other, is linear orbranched and has from one to four carbon atoms, the trialkylsilyl aminogroups wherein each alkyl group, identical or different from the other,is linear or branched and has from one to four carbon atoms, theamidinates groups and the carbonyl, being understood that, if saidformula (II) comprises more than one R′ groups, each R′ may be identicalor different one from another,

to form a first gas phase metal source;

-   -   Optionally a step b′) of vaporizing at least one M² metal        containing precursor, M² being as hereinabove defined; to form        an optional second gas phase metal source;    -   A step c) of introducing said first gas phase metal source and        said optional second gas phase metal source, in the reaction        chamber, in order to provoke their contact with said substrate,        to generate the deposition of a metal containing dielectric film        comprising a compound of the formula (I) as hereinbefore        defined, on said substrate;    -   provided that, if the at least one metal containing dielectric        film to be formed comprises the compound of the formula (I′):        M¹ ₁O₂  (I′),        corresponding to the formula (I), as hereinbefore defined        wherein, a=0, b=2, and c=0, and if the M¹ metal containing        precursor, which is involved in step b), is a compound of the        formula (II′):        (R² _(t)Cp)₂M¹R′₂  (II′),        corresponding to the formula (II) as hereinabove defined wherein        x=0, and z=2, in said formula (II′), t>0 in at least one of the        two (R² _(t)Cp) ligands.

In the method as hereinabove defined, the at least one metal containingprecursor of the formula (II) and if necessary, the least one M² metalcontaining precursor, have a melting point generally below 50° C.,preferably below 35° C. and they are preferably liquid at roomtemperature.

According to a particular embodiment of the method as hereinbeforedefined, the vaporization step b) and if necessary, the vaporizationstep b′) are achieved by introducing a carrier gas into a heatedcontainer containing the at least one M¹ metal containing precursor ofthe formula (II):(R¹ _(y)Op)_(x)(R² _(t)Cp)_(z)M¹R′_(4-x-z)  (II)and if necessary, both the at least one M² metal containing precursor.The container is preferably heated at a temperature allowing to get thesaid metal sources in liquid phase and at a sufficient vapor pressure.If necessary, one or both metal precursors may be mixed to a solvent orto a mixture of solvents and/or to a stabilizer. The said solvent is forexample selected from octane, hexane, pentane or tetramethylsilane. Theconcentration of the metal precursors in the solvant or in the mixtureof solvents is usually between 0.01M and 0.5M and is more particularlyaround 0.05M. The carrier gas is selected, without limitation, from Ar,He, H₂, N₂ or mixtures of thereof. If necessary, the container may beheated at temperatures in the range of 80-110° C. Those skilled in theart will consider that the temperature of the container can be adjustedto control the amount of precursor to be vaporized.

The carrier gas flow is usually comprised between 10 sccm (standardcubic centimeter) and 500 sccm. Preferably, the carrier gas flow iscomprised between 50 sccm and 200 sccm.

According to another particular embodiment of the method as hereinbeforedefined, the vaporization step b) and if necessary, the vaporizationstep b′) are achieved by introducing in a liquid form, the M¹ metalcontaining precursor of the formula (II):(R¹ _(y)Op)_(x)(R² _(t)Cp)_(z)M¹R′_(4-x-z)  (II)and if necessary both the M² metal containing precursor to a vaporizerwhere it is vaporized. If necessary, one or both metal precursors may bemixed to a solvent or to a mixture of solvents and/or to a stabilizer.The said solvent is for example selected from octane, hexane, pentane ortetramethylsilane. The concentration of the metal precursors in thesolvent or in the mixture of solvents is usually between 0.01M and 0.5Mand is more particularly around 0.05M.

According to a more particular embodiment, the vaporization step b) andthe vaporization step b′) are combined in one vaporization step b″) ofboth sources.

During the step c) of the method as hereinbefore defined, the vaporizedmetal containing precursor is introduced into a reaction chamber whereit is contacted to a substrate.

In the context of the present invention, substrate means any substrateused in the semiconductors manufacturing, which, because of theirtechnical function, requires to be coated by metal containing films.Such substrates are for example not only selected from siliconsubstrates (Si), silica substrates (SiO₂), silicon nitride substrates(SiN) or silicon oxy nitride substrates (SiON), but also from tungstensubstrates (W) or noble metal substrates such as for example, Platinumsubstrates (Pt), Palladium substrates (Pd), Rhodium substrates (Rh) orgold substrates (Au).

The substrate is heated until the required temperature to obtain thedesired film with a sufficient growth rate and with the desired physicalstate and composition.

The temperature during step c), usually ranges from 150° C. to 600° C.Preferably the temperature is lower or equal to 450° C.

The pressure in the reaction chamber is controlled to obtain the desiredmetal containing film with a sufficient growth rate. The pressure duringstep c) usually ranges from around 1 mTorr (0.1333224 Pa) to around 100Torr (13332.24 Pa).

In the context of the present invention, the M² metal containingprecursor, is selected from the group consisting of:

Silicon derivatives or their Germanium homologues, such as:

disiloxane, trisilylamine, disilane, trisilane, alkoxysilane of theformula: (III₁)SiH_(x)(OR³)_(4-x),  (III₁)wherein: 0≦x≦3 and R³ represents a linear or branched hydrocarbon grouphaving 1 to 6 carbon atoms;silanol derivative of the formula (III₂):Si(OH)_(x)(OR⁴)_(4-x)  (III₂)wherein: 0≦x≦3 and R⁴ represents a linear or branched alkyl group,having 1 to 6 carbon atoms, preferably Si(OH)(OR⁴)₃ and more preferablySi(OH)(OtBu)₃; aminosilane derivative of the formula (III₃):SiH_(x)(NR⁵R⁶)_(4-x)  (III₃)wherein: 0≦x≦3 and R⁵ and R⁶ are identical or different andindependently represents an hydrogen atom or a linear or branched alkylhaving 1 to 6 carbon atoms, preferably SiH(NMe₂)₃ (TriDMAS);SiH₂(NHtBu)₂ (BTBAS); SiH₂(NEt₂)₂ (BDEAS)) and mixtures thereof;

Aluminum derivatives, such as trimethylaluminum [Al(CH₃)₃], dimethylaluminum hydride [AlH(CH₃)₂], alkoxyalane of the formula (IV₁):AlR⁸ _(x)(OR⁷)_(3-x)  (IV₁)wherein: 0≦x≦3 and R⁷ represents a linear or branched alkyl having 1 to6 carbon atom, and R⁸, identical to or different from R⁷, represents anhydrogen atom, or preferably AlR⁹R¹⁰(OR⁷), with R⁹ and R¹⁰ identical ordifferent, which independently represent an linear or branched alkylhaving 1 to 6 carbon atoms, most preferably AlMe₂(OiPr);amidoalane of the formula (IV₂):AlR¹¹ _(x)(NR¹²R¹³)_(3-x)  (IV₂)wherein: 0≦x≦3 and R¹² and R¹³ identical or different, represent anhydrogen atom or a linear or branched alkyl having 1 to 6 carbon atoms,and R¹¹, identical to or different from R⁷ and, represents an hydrogenatom or a linear or branched alkyl having 1 to 6 carbon atoms;

Tantalum derivatives, such as: Ta(OMe)₅, Ta(OEt)₅, Ta(NMe₂)₅, Ta(NEt₂)₅,Ta(NEt₂)₅, a tantalum derivative of the formula (V₁):Ta(OR¹⁴)₄[O—C(R¹⁵)(R¹⁶)—CH₂—OR¹⁷]wherein R¹⁴, R¹⁵, R¹⁶ and R¹⁷, identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms, preferably Ta(OEt)₄(OCMe₂CH₂—OMe) (TAT-DMAE), a tantalumderivative of the formula (V₂):Ta(OR¹⁸)₄[O—C(R¹⁹)(R²⁰)—CH₂—N(R²¹)(R²²)]  (V₂)wherein R¹⁸, R¹⁹, R²⁰, R²¹ and R²² identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms, a tatalum derivative of the formula (V₃):Ta(═NR²⁴)(NR²⁵R²⁶)₃  (V₃)wherein R²⁴, R²⁵ and R²⁶, identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms;

Niobium derivatives, such as Nb(OMe)₅, Nb(OEt)₅, Nb(NMe₂)₅, Nb(NEt₂)₄,Nb(NEt₂)₅, a niobium derivative of the formula (VI₁):Nb(OR²⁷)₄(O—C(R²⁸)(R²⁹)—CH₂—OR³⁰)  (VI₁)wherein R²⁷, R²⁸, R²⁹ and R³⁰, identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms, preferably Nb(OEt)₄(OCMe₂CH₂—OMe) (NBT-DMAE), a niobiumderivative of the formula (VI₂):Nb(OR³¹)₄[O—C(R³²)(R³³)—CH₂—N(R³⁴)(R³⁵)]  (VI₂)wherein R³¹, R³², R³³, R³⁴ and R³⁵ identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms, a niobium derivative of the formula (VI₃):Nb(═NR³⁶)(NR³⁷R³⁸)₃  (VI₃)wherein R³⁶, R³⁷ and R³⁸, identical or different, independentlyrepresent an hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms;

lanthanide derivatives, such as scandium derivatives, yttriumderivatives, cerium derivatives, praseodinum derivatives, gadoliniumderivatives, dysprosium derivatives, erbium derivatives, lanthanumderivatives, a derivative with at least one β-diketonate ligand or atleast a cyclopentadienyl ligand optionally substituted with one orseveral linear or branched alkyl groups having 1 to 6 carbon atoms;

divalent metal derivatives, such as strontium (Sr), barium (Ba),magnesium (Mg), calcium (Ca) or zinc (Zn) derivatives, with at least oneβ-diketonate ligand or at least a cyclopentadienyl ligand optionallysubstituted with one or several linear or branched alkyl groups having 1to 6 carbon atoms;

other metal derivatives such as tungsten (W), molybdenum (Mo), hafnium(Hf) or zirconium (Zr) derivatives, for example the alkoxy derivatives,the amino derivatives or adducts containing these species, beingunderstood that said derivatives are not compounds of the formula (II)as hereinbefore defined.

According to another particular embodiment, the method as hereinbeforedefined, comprise:

-   -   A step d), wherein the at least one M¹ metal containing        precursor of the formula (II), and if necessary, the at least        one M² metal containing precursor, is mixed to at least one        reactant specie prior to step c).

In the context of the invention, the at least one reactant specie ischosen in relation to the targeted metal based film, which is expectedAccording to another embodiment, the reactant specie is an oxygen sourceand more particularly oxygen (O₂), oxygen containing radicals O. or OH.,for instance generated by a remote plasma, ozone (O₃), moisture (H₂O)and H₂O₂ and mixture thereof.

According to another embodiment, the reactant specie is a nitrogensource and more particularly nitrogen (N₂), nitrogen-containing radicalssuch as N., NH., NH₂., ammonia (NH₃), hydrazine (NH₂NH₂) and its alkylor aryl derivatives, and mixtures thereof.

According to another embodiment, the reactant specie is both a nitrogenand an oxygen source and more particularly, NO, NO₂, N₂O, N₂O₅, N₂O₄ andmixtures thereof.

Depending on the ratio N/O, which is required, the reactant specie whichis, if necessary, used in the method as hereinbefore defined, may beeither an oxygen source, either a mixture of an oxygen source and of anitrogen source either both an oxygen and a nitrogen source or a mixturethereof.

According to another embodiment of the invention, if the targeted metalbased film contains carbon, such as for example without limitation metalcarbide or metal carbonitride, at least one reactant specie is a carbonsource more particularly, methane, ethane, propane, butane, ethylene,propylene, t-butylene,

According to another embodiment of the invention if the targeted metalbased film contains silicon, such as for example without limitationmetal silicide, silico-nitride, silicate or silico-carbo-nitride, atleast on reactant specie is a silicon source such as:

disiloxane, trisilylamine, disilane (Si₂H₆), trisilane (Si₃H₈),alkoxysilane of the formulas (III₁), (III₂) or (III₃), as hereinbeforedefined, for example SiH(NMe₂)₃ (TriDMAS); SiH₂(NHtBu)₂ (BTBAS);SiH₂(NEt₂)₂ (BDEAS)) and mixtures thereof.

According to another particular embodiment, the method as hereinbeforedefined, comprise:

-   -   a step d′) wherein the at least one M¹ metal containing        precursor of the formula (II) and if necessary, the at least one        M² metal containing precursor, is mixed to at least one reactant        specie in the reaction chamber.

The mode of introduction of the at least one M¹ metal containingprecursor of the formula (II) and if necessary, the at least one M²metal containing precursor, and the at least one reactant specie in thereaction chamber generally depends on the mode of deposition of the filmon the substrate. The metal containing precursors and the reactantspecies are generally introduced simultaneously in a chemical vapordeposition process, or sequentially in an atomic layer depositionprocess or according to several combinations, as for example in a pulsedmodified atomic layer deposition process wherein the at least one M¹metal containing precursor of the formula (II) and if necessary, the atleast one M² metal containing precursor, are introduced together in onepulse and the at least one reactant specie is introduced in a separatepulse; or in a pulsed chemical vapor deposition process wherein the atleast one M¹ metal containing precursor of the formula (II) and ifnecessary, the at least one M² metal containing precursor, areintroduced by pulse and the at least one reactant specie is introducedcontinuously.

According to another of the invention, the at least one reactant specieis passed through a plasma system localized remotely from the reactionchamber, and decomposed to radicals.

According to another embodiment, the step (b) of the method ashereinabove defined, consists of a step (b₁) of mixing at least onefirst metal containing precursor of the formula (II) together with atleast a second of the following precursors: M¹(NMe₂)₄, M¹(NEt₂)₄,M¹(NMeEt)₄, M¹(mmp)₄, M¹(OtBu)₄, M¹(OtBu)₂(mmp)₂ and mixtures thereofand a step (b₂) of vaporizing said mixture.

According to a more particular embodiment, the invention concerns amethod as hereinbefore defined, of deposition of a metal containingdielectric film comprising a compound of the formula (I), wherein the M¹metal containing precursor is of the formula (II₁):(R² _(t)Cp)M¹[N(R³⁹)(R⁴⁰)]₃  (II₁)corresponding to the formula (II), wherein x=0 z=1 and R′ represents thegroup N(R³⁹)(R⁴⁰), wherein R³⁹ and R⁴⁰, identical or different,independently represent an hydrogen atom, a linear or branched alkylgroup having from one to four carbon atoms, an alkylsilyl group, whereinthe alkyl group is linear or branched and has from one to four carbonatoms, a dialkylsilyl group, wherein each alkyl group, identical ordifferent from the other, is linear or branched and has from one to fourcarbon atoms or a trialkylsilyl group wherein each alkyl group,identical or different from the other, is linear or branched and hasfrom one to four carbon atoms

According to a more particular embodiment, the invention concerns amethod as hereinbefore defined, of deposition of a metal containingdielectric film comprising a compound of the formula (I₁):M¹O₂  (I₁)corresponding to the formula (I), wherein a=0, b=2 and c=0 wherein themetal containing precursor of the formula (II) is selected from thegroup consisting of: HfCP₂Cl₂, Hf(MeCp)₂Me₂, HfCp(MeCp)Cl₂,Hf(MeCp)₂Cl₂, HfCp(MeCp)Me₂, Hf(EtCp)(MeCp)Me₂, Hf(EtCp)₂Me₂,Hf(MeCp)₂(CO)₂, ZrCP₂Cl₂, Zr(MeCp)₂Me₂, ZrCp(MeCp)Cl₂, Zr(MeCp)₂Cl₂,ZrCp(MeCp)Me₂, Zr(EtCp)(MeCp)Me₂, Zr(EtCp)₂Me₂, Zr(MeCp)₂(CO)₂,Zr(MeCp)(NMe₂)₃, Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃,Zr(EtCp)(NEtMe)₃, ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃,ZrCp(NEt₂)₃, Zr(iPr₂Cp)(NMe₂)₃, Zr(tBu₂Cp)(NMe₂)₃, Hf(MeCp)(NMe₂)₃,Hf(EtCp)(NMe₂)₃, HfCp(NMe₂)₃, Hf(MeCp)(NEtMe)₃, Hf(EtCp)(NEtMe)₃,HfCp(NEtMe)₃, Hf(MeCp)(NEt₂)₃, Hf(EtCp)(NEt₂)₃, HfCp(NEt₂)₃,Hf(iPr₂Cp)(NMe₂)₃, Hf(tBu₂Cp)(NMe₂)₃ and mixtures thereof.

According to a more particular embodiment, the invention concerns amethod as hereinbefore defined, of deposition of a metal containingdielectric film comprising a compound of the formula (I₂):M¹O_(b)N_(c),  (I₂)corresponding to the formula (I), wherein a=0, 1.5≦b≦2.5 and 0<c≦0.5,wherein the metal containing precursor of the formula (II) is selectedfrom the group consisting of: HfCP₂Cl₂, Hf(MeCp)₂Me₂, HfCp(MeCp)Cl₂,Hf(MeCp)₂Cl₂, HfCp(MeCp)Me₂, Hf(EtCp)(MeCp)Me₂, Hf(EtCp)₂Me₂,Hf(MeCp)₂(CO)₂, ZrCP₂Cl₂, Zr(MeCp)₂Me₂, Zr(MeCp)₂Cl₂, ZrCp(MeCp)Me₂,Zr(EtCp)(MeCp)Me₂, Zr(EtCp)₂Me₂, Zr(MeCp)₂(CO)₂, Zr(MeCp)(NMe₂)₃,Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃, Zr(EtCp)(NEtMe)₃,ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃, ZrCp(NEt₂)₃,Zr(iPr₂Cp)(NMe₂)₃, Zr(tBu₂Cp)(NMe₂)₃, Hf(MeCp)(NMe₂)₃, Hf(EtCp)(NMe₂)₃,HfCp(NMe₂)₃, Hf(MeCp)(NEtMe)₃, Hf(EtCp)(NEtMe)₃, HfCp(NEtMe)₃,Hf(MeCp)(NEt₂)₃, Hf(EtCp)(NEt₂)₃, HfCp(NEt₂)₃, Hf(iPr₂Cp)(NMe₂)₃,Hf(tBu₂Cp)(NMe₂)₃ and mixture thereof.

According to a more particular embodiment, the invention concerns amethod as hereinbefore defined, of deposition of a metal containingdielectric film comprising a compound of the formula (I₃):(M¹ _(1-a)M² _(a))O_(b)  (I₃)corresponding to the formula (I), wherein 0≦a<1 and c=0, wherein themetal containing precursor of the formula (II) is selected from thegroup consisting of: HfCP₂Cl₂, Hf(MeCp)₂Me₂, HfCp(MeCp)Cl₂,Hf(MeCp)₂Cl₂, HfCp(MeCp)Me₂, Hf(EtCp)(MeCp)Me₂, Hf(EtCp)₂Me₂,Hf(MeCp)₂(CO)₂, ZrCP₂Cl₂, Zr(MeCp)₂Me₂, ZrCp(MeCp)Cl₂, Zr(MeCp)₂Cl₂,ZrCp(MeCp)Me₂, Zr(EtCp)(MeCp)Me₂, Zr(EtCp)₂Me₂, Zr(MeCp)₂(CO)₂,Zr(MeCp)(NMe₂)₃, Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃,Zr(EtCp)(NEtMe)₃, ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃,ZrCp(NEt₂)₃, Zr(iPr₂Cp)(NMe₂)₃, Zr(tBu₂Cp)(NMe₂)₃, Hf(MeCp)(NMe₂)₃,Hf(EtCp)(NMe₂)₃, HfCp(NMe₂)₃, Hf(MeCp)(NEtMe)₃, Hf(EtCp)(NEtMe)₃,HfCp(NEtMe)₃, Hf(MeCp)(NEt₂)₃, Hf(EtCp)(NEt₂)₃, HfCp(NEt₂)₃,Hf(iPr₂Cp)(NMe₂)₃, Hf(tBu₂Cp)(NMe₂)₃ and the M² metal containingprecursor is preferably selected from the silicon derivatives or theirgermanium homologues, the tantalum derivatives, lanthanide derivatives,and the magnesium derivatives as hereinabove defined.

According to a more particular embodiment, the invention concerns amethod as hereinbefore defined, of deposition of a metal containingdielectric film comprising a compound of the formula (I₄):(M¹ _(1-a)M² _(a))O_(b)N_(c)  (I₄)corresponding to the formula (I), wherein 0≦a<1 and 0<c≦0.5, wherein themetal containing precursor of the formula (II) is selected from thegroup consisting of HfCP₂Cl₂, Hf(MeCp)₂Me₂, HfCp(MeCp)Cl₂, Hf(MeCp)₂Cl₂,HfCp(MeCp)Me₂, Hf(EtCp)(MeCp)Me₂, Hf(EtCp)₂Me₂, Hf(MeCp)₂(CO)₂,ZrCP₂Cl₂, Zr(MeCp)₂Me₂, ZrCp(MeCp)Cl₂, Zr(MeCp)₂Cl₂, ZrCp(MeCp)Me₂,Zr(EtCp)(MeCp)Me₂, Zr(EtCp)₂Me₂, Zr(MeCp)₂(CO)₂, Zr(MeCp)(NMe₂)₃,Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃, Zr(EtCp)(NEtMe)₃,ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃, ZrCp(NEt₂)₃,Zr(iPr₂Cp)(NMe₂)₃, Zr(tBu₂Cp)(NMe₂)₃, Hf(MeCp)(NMe₂)₃, Hf(EtCp)(NMe₂)₃,HfCp(NMe₂)₃, Hf(MeCp)(NEtMe)₃, Hf(EtCp)(NEtMe)₃, HfCp(NEtMe)₃,Hf(MeCp)(NEt₂)₃, Hf(EtCp)(NEt₂)₃, HfCp(NEt₂)₃, Hf(iPr₂Cp)(NMe₂)₃,Hf(tBu₂Cp)(NMe₂)₃, the M² metal containing precursor is preferablyselected from the silicon derivatives or their germanium homologues, thetantalum derivatives, lanthanide derivatives, and the magnesiumderivatives as hereabove defined, and at least one oxygen containingprecursor and at least one nitrogen containing precursor is introducedinto the reactor.

According to another embodiment the invention concerns the use of thecompounds of the formula (II) as hereinbefore defined, to makedielectric films more particularly for integrated circuits or in thepreparation of Metal Insulator Metal (MIM) architectures for RandomAccess Memories.

According to another embodiment, the invention concerns a compound theformula (II₁):(R² _(t)CP)M¹[N(R³⁹)(R⁴⁰)]₃  (II₁)corresponding to the formula (II), wherein x=0, z=1 and R′ representsthe group N(R³⁹)(R⁴⁰), wherein R³⁹ and R⁴⁰, identical or different,independently represent an hydrogen atom, a linear or branched alkylgroup having from one to four carbon atoms, an alkylsilyl group, whereinthe alkyl group is linear or branched and has from one to four carbonatoms, a dialkylsilyl group, wherein each alkyl group, identical ordifferent from the other, is linear or branched and has from one to fourcarbon atoms or a trialkylsilyl group wherein each alkyl group,identical or different from the other, is linear or branched and hasfrom one to four carbon atoms.

According to a particular embodiment, the invention relates to acompound of the formula (II₁) as hereinbefore defined, wherein R², R³⁹and R⁴⁰, identical or different, independently represent a radicalselected from the methyl, ethyl, propyl, isopropyl, butyl, isobutyl,sec-butyl and tert-butyl groups, and more specifically the followingcompounds:

Zr(MeCp)(NMe₂)₃, Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃,Zr(EtCp)(NEtMe)₃, ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃,ZrCp(NEt₂)₃, Zr(iPr₂Cp)(NMe₂)₃, Zr(tBu₂Cp)(NMe₂)₃, Hf(MeCp)(NMe₂)₃,Hf(EtCp)(NMe₂)₃, HfCp(NMe₂)₃, Hf(MeCp)(NEtMe)₃, Hf(EtCp)(NEtMe)₃,HfCp(NEtMe)₃, Hf(MeCp)(NEt₂)₃, Hf(EtCp)(NEt₂)₃, HfCp(NEt₂)₃,Hf(iPr₂Cp)(NMe₂)₃, Hf(tBu₂Cp)(NMe₂)₃.

According to a more specific embodiment, the invention relates to thefollowing compounds:

Zr(EtCp)(NMe₂)₃, Zr(MeCp)(NMe₂)₃, ZrCp(NMe₂)₃, Hf(EtCp)(NMe₂)₃,Hf(MeCp)(NMe₂)₃ and HfCp(NMe₂)₃.

Those skilled in the art will recognize that the hereinabovemetal-organic compounds could be used for any other applications thanvapour phase deposition processes, such as catalysts or any otherindustrial process or application requiring the use of metal-organiccompounds . . . .

According to another embodiment, the invention concerns a process forthe preparation of a compound of the formula (II₁) as hereinabovedefined, which comprises:

a step 1, consisting of the preparation of the compound of the formula(VII₁):(R² _(t)CP)M¹Cl₃  (VII₁)wherein M¹, R² and t are as hereinabove defined for the formula (II), bythe reaction of M¹Cl₄ with (R² _(t)Cp)Na;

a step 2, consisting of the reaction of the compound of the formula(VII₁) prepared in step 1, with NH(R³⁹)(R⁴⁰), to produce the compound ofthe formula (II₁).

According to a last embodiment, the invention concerns the followingcompounds of the formula (II) as hereinabove defined:

Hf(EtCp)₂Me₂, Zr(MeCp)₂Me₂ or Zr(EtCp)₂Me₂.

The following examples are an illustration of the various embodiments ofthe present invention, without being a limitation.

Example I Deposition of Metal Oxide Film M¹O₂ with M¹ Being PreferablyHafnium and Zirconium

The film to be deposited comprises a compound of the formula (I) whereina=0, b=2 and c=0.

To make the deposition of such film on the surface of a wafer or in adeep trench to manufacture MIM structures for DRAM, one need to vaporizethe M¹ metal source as defined in step (b) and to introduce it into thereactor (preferably Hafnium or Zirconium), to inject an oxygen source,preferably moisture, oxygen or ozone into said reactor, react theproducts at appropriate temperature (preferably between 150° C. and 350°C.) and pressure (preferably between 25 Pa and 1000 Pa) for the durationnecessary to achieve either a thin film deposition on the substrate orto fill out deep trenches by ALD or pulse CVD process (sequential pulseinjection of metal sources are necessary in order to allow regulardeposition of the oxide in the trench to progressively fill out thistrench and provide no voids in the dielectric film and therefore nodefect in the capacitor dielectric film).

The dielectric film shall have the desired final composition (hereessentially variations of the b value around 2 modifying the ratio ofprecursor to oxygen source).

Three examples of types of compounds of the formula (II) were chosenaccording to the three following options a, b or c:

a) The compound of the formula (II) is chosen from Zr(MeCp)₂Me₂,Zr(EtCp)₂Me₂, Hf(MeCp)₂Me₂ and Hf(MeCp)₂Me₂.

Delivery of molecules in liquid form is usually carried out by bubblingan inert gas (N₂, He, Ar, . . . ) into the liquid and providing theinert gas plus liquid gas mixture to the reactor.

b) The compound of the formula (II) is chosen from Zr(2,4-Me₂Op)₂Me₂ andHf(2,4-Me₂Op)₂Me₂.

c) The compound of the formula (II) is chosen fromZr(MeCp)(2,4-Me₂Op)Me₂ and Hf(MeCp)(2,4-Me₂Op)Me₂.

The oxygen source shall be preferably, without limitations, oxygen (O₂),oxygen radicals (for instance O. or OH.), such as radicals generated bya remote plasma system, ozone, NO, N₂O, NO₂, moisture (H₂O) and H₂O₂.

Regarding the deposition process by itself, the reactants can beintroduced into the reactor simultaneously (chemical vapor deposition),sequentially (atomic layer deposition) or different combinations (oneexample is to introduce metal source and the other metal source togetherin one pulse and oxygen in a separate pulse [modified atomic layerdeposition]; another option is to introduce oxygen continuously and/orto introduce the metal source by pulse (pulsed-chemical vapordeposition).

Example II Deposition of Metal Oxynitride Films M¹ON with M¹ BeingPreferably Hafnium and Zirconium

The film to be deposited comprises a compound of the formula (I) whereina=0 and b and c are different from zero.

All the information given in Example I, is applicable in this ExampleII, except that nitrogen needs to be introduced into the reactor.

The nitrogen shall be selected from a nitrogen source selected from thegroup comprising nitrogen (N₂), ammonia, hydrazine and alkylderivatives, N-containing radicals (for instance N., NH., NH₂.), NO,N₂O, NO₂ or the like.

Example III Deposition of M¹M² Metal Oxide Films with M¹ beingPreferably Hf or Zr and M² Being Preferably Si or Al

The film to be deposited comprises a compound of the formula (I) whereina≠0, b≠0 and c=0.

All the information given in Example I, is applicable in this ExampleIII, except that a M² metal source is additionally needed.

The M² containing precursor is also introduced into the reactor to cratethe M² source of metal. This M² containing precursor source shall bepreferably:

a) a silicon (or germanium) source, for example Si(OH)(OtBu)₃,SiH(NMe₂)₃ (TriDMAS); SiH₂(NHtBu)₂ (BTBAS) and SiH₂(NEt₂)₂ (BDEAS)

b) an aluminum source, for example AlMe₂(OiPr); or

c) a tantalum (or niobium) source, for example Ta(OMe)₅, Ta(OEt)₅ andTa(OEt)(OCMe₂CH₂—OMe) (TATDMAE);

The invention is directed to the deposition of dielectric films of theformula I, onto a support such as a wafer, in a reactor using ALD, CVD,MOCVD, pulse CVD processes.

Example IV Deposition of M¹M² Metal Oxynitride Films with M¹ beingPreferably Hf or Zr and M² being Preferably Si or Al

The film to be deposited comprises a compound of the formula (I) whereina≠0, b≠0 and c≠0.

All the information given in Example III, is applicable in this case,except that nitrogen needs to be introduced into the reactor.

The nitrogen source shall be selected from the group comprising nitrogen(N2), ammonia, hydrazine and alkyl derivatives, N-containing radicals(for instance N. NH., NH₂.), NO, N₂O, NO₂.

Example V Synthesis of(ethylcyclopentadienyl)tris(dimethylamino)zirconium, Zr(EtCp)(NMe₂)₃

Zr(EtCp)(NMe₂)₃ is prepared in 3 steps.

The first step is the preparation of Zr(EtCp)Cl₃ by the reaction of(EtCp)Na over ZrCl₄;

The second step is the reaction LiNMe₂ with Zr(EtCp)Cl₃ to produceZr(EtCp)(NMe₂)₃. The resulting compound is purified by distillation.Overall yield was 35%.

(Ethylcyclopentadienyl)tris(dimethylamino)zirconium has been found to bea stable liquid pale yellow compound.

TGA Analysis of Zr(EtCp)(NMe₂)₃

The thermal gravimetric apparatus was stored in an argon glove box withmoisture and oxygen content maintained below 1 ppmv. Thermal gravimetricanalysis was performed by placing a 35 mg sample in an aluminumcrucible. The sample was then heated at a 10° C./min temperature rampfrom 35° C. to 400° C. The mass loss was monitored as a function of thecrucible temperature. The residue level was 2.6% with full evaporationtemperatures of 260° C. The resulting graph is on FIG. 1.

Example VI Atomic Layer Deposition of ZrO₂ Thin Films UsingZr(EtCp)(NMe₂)₃

Zr(EtCp)(NMe₂)₃ is stored into a container. The container is heated at90° C. and N₂ is used as carrier gas at a flow of 50 sccm. The pressurethe container is controlled at 50 Torr. O₃ is used as oxygen source. Thesubstrate is heated at 350° C. During a first step, Zr(EtCp)(NMe₂)₃ isintroduced into the reaction chamber during 2 s. A N₂ purge of 5 s isperformed afterwards as second step. As third step, a pulse of O₃ isthen introduced into the reaction chamber during 2 s, followed by a 2 sN₂ purge as fourth step. All four steps are repeated 100 times to obtaina ZrO₂ film. Self-limited atomic layer deposition is obtained.

Similar experiments can be performed with Hf analogs. Similarexperiments can be conducted with H₂O as oxygen source.

Example VII Metal-Organic Chemical Vapor Deposition of ZrO₂ UsingZr(EtCp)(NMe₂)₃

Zr(EtCp)(NMe₂)₃ is stored into a container. The container is heated at90° C. and N₂ is used as carrier gas at a flow of 50 sccm. The pressurein the container is controlled at 50 Torr. Zr(EtCp)(NMe₂)₃ is mixed toan O₂/N₂ gas mixture into the reaction chamber. The substrate is heatedat 500° C. The pressure inside the reaction chamber is set at 10 Torr. Afilm of zirconium oxide is obtained.

Similar experiments can be performed with Hf analogs.

Example VIII Comparison of Zr(EtCp)(NMe₂)₃ and Zr(NEtMe)₄ ThermalBehavior

Thermal gravimetric analysis is performed on Zr(EtCp)(NMe₂)₃ andZr(NEtMe)₄ in similar conditions. Thermal gravimetric apparatus wasstored in an argon glove box with moisture and oxygen content maintainedbelow 1 ppmv. Thermal gravimetric analysis was performed by placing a 35mg sample in an aluminum crucible. The sample was then heated at a 10°C./min temperature ramp from 35° C. to 400° C. The mass loss wasmonitored as a function of the crucible temperature. In closed cupconfiguration, a pierced pan (0.8 mm) is placed over the cruciblecontaining the metal-organic compound to slow down the evaporation. Thisindicates the thermal stability at higher temperature. The resultsindicates that Zr(EtCp)(NMe₂)₃ is much more thermally stable thanZr(NEtMe)₄, making it further attractive for use as vapor phaseprecursor. The results are shown on FIG. 2.

Example IX Synthesis and Thermal Behavior of Hf(EtCp)₂Me₂

Hf(EtCp)₂Cl₂ is readily obtained by the reaction of 1 mole HfCl₄ overEtCpNa.

Hf(EtCp)₂Me₂ is then obtained by a slow addition of 2 moles LiMe over 1mole Hf(EtCp)₂Cl₂ at −20° C. and increasing the temperature until 0° C.The obtained transparent liquid Hf(EtCp)₂Me₂ is separated from LiCl andsolvent by distillation. TGA analysis of Hf(EtCp)₂Me₂ in vacuumconditions, leaves a residue of 1.0% for a starting mass of about 30 mg.(see FIG. 3)

Example X Atomic Layer Deposition of HfO₂ from Hf(EtCp)₂Me₂ and O₃

This example concerns the fabrication of hafnium oxide films. A siliconwafer is mounted in a deposition chamber that is provided with a heaterover its circumference and the desired film is formed on the surface ofthe silicon wafer. The chamber is evacuated by a pump. The metalprecursor, in this case dimethylhafnocene HfMe₂(EtCp)₂, is stored in aheated liquid container. Nitrogen gas is used as the carrier gas for theHf(EtCp)₂Me₂. The Hf(EtCp)₂Me₂ in the liquid container is transported byflowing the nitrogen through the liquefied material. Nitrogen istransported through a mass flow controller into the vaporizer. TheHf(EtCp)₂Me₂ vapors were carried by nitrogen and fed to the chamberalong, or diverted to a bypass line when the valve allowing theintroduction of the precursor into the reactor is closed. Anoxygen/ozone gas mixture (oxidizing agent) is also fed through a massflow controller either into the chamber or to a bypass line.Oxygen/ozone on one side and Hf(EtCp)₂Me₂ on the other side were neverintroduced together to avoid a highly probable CVD reaction. They wereusually introduced one by one, each reactant pulse being separated bypurge time where only N₂ was introduced into the chamber.

Hafnium oxide films were produced at a ˜0.7 A/cycle under the followingconditions using the described tool:

Pressure=3 torr, temperature=350° C., Hf(EtCp)₂Me₂ flow rate=0.5 sccm,O₂ flow rate=100 sccm. O₃ flow rate=8 sccm.N₂ flow rate=100 sccm.

An Auger profile of the obtained film is given as example (See FIG. 4).

It will be understood that many additional changes in the details,materials, steps and arrangement of parts, which have been hereindescribed in order to explain the nature of the invention, may be madeby those skilled in the art within the principle and scope of theinvention as expressed in the appended claims. Thus, the presentinvention is not intended to be limited to the specific embodiments inthe examples given above.

What is claimed is:
 1. A method of deposition on a substrate, of atleast one metal containing dielectric film comprising a compound of theformula (I):(M¹ _(1-a)M² _(a))O_(b)N_(c),  (I) wherein: 0≦a<1, 0<b≧3; 0≦c≦1, M¹ iszirconium (Zr); and M² represents a metal atom selected from magnesium(Mg), calcium (Ca), zinc (Zn), boron (B), aluminum (Al), indium (In),silicon (Si), germanium (Ge), tin (Sn), hafnium (Hf), zirconium (Zr),titanium (Ti), vanadium (V), niobium (Nb), tantalum (Ta); and theLanthanides atoms and rare-earth metal atoms, which comprises thefollowing steps: a step a) of providing a substrate into a reactionchamber; a step b) of vaporizing at least one M¹ metal containingprecursor to form a first gas phase metal source, the at least one M¹metal containing precursor is selected from the group consisting ofZr(MeCp)(NMe₂)₃, Zr(EtCp)(NMe₂)₃, ZrCp(NMe₂)₃, Zr(MeCp)(NEtMe)₃,Zr(EtCp)(NEtMe)₃, ZrCp(NEtMe)₃, Zr(MeCp)(NEt₂)₃, Zr(EtCp)(NEt₂)₃,ZrCp(NEt₂)₃, Zr(iPr₂Cp)(NMe₂)₃, and Zr(tBu₂ Cp)(NMe₂)₃; optionally astep b′) of vaporizing at least one M² metal containing precursor, M²being as hereinabove defined, to form an optional second gas phase metalsource; a step c) of introducing said first gas phase metal source andsaid optional second gas phase metal source, in the reaction chamber, inorder to provoke their contact with said substrate, to generate thedeposition of a metal containing dielectric film comprising a compoundof the formula (I) as hereinbefore defined, on said substrate.
 2. Themethod of claim 1, wherein the vaporization step b) and the vaporizationstep b′) are combined in one vaporization step b″) of both sources. 3.The method of claim 1, wherein the M² metal containing precursor, isselected from the group consisting of: silicon derivatives or theirgermanium homologues; silanol derivative of the formula (III₂):Si(OH)_(x)(OR⁴)_(4-x)  (III₂) wherein: 1≦x≦3 and R⁴ represents a linearor branched alkyl group, having 1 to 6 carbon atoms; aminosilanederivative of the formula (III₃):SiH_(x)(NR⁵R⁶)_(4-x)  (III₃) wherein; 0≦x≦3 and R⁵ and R⁶ are identicalor different and independently represents an hydrogen atom or a linearor branched alkyl having 1 to 6 carbon atoms; aluminum derivatives;amidoalane of the formula (IV₂):AlR¹¹(NR¹²R¹³)_(3-x)  (IV₂) wherein: 0≦x≦3 and R¹² and R¹³ identical ordifferent, represent an hydrogen atom or a linear or branched alkylhaving 1 to 6 carbon atoms, and R¹¹, identical to or different from R⁷and, represents an hydrogen atom or a linear or branched alkyl having 1to 6 carbon atoms; tantalum derivatives; Niobium derivatives; lanthanidederivatives; divalent metal derivatives; and other metal derivatives. 4.The method of claim 3, wherein the metal containing dielectric filmcomprises a compound of the formula (I₃):(M¹ _(1-a)M² _(a))O_(b)  (I₃) corresponding to the formula (I), wherein0≦a<1 and c=0, wherein the M² metal containing precursor is selectedfrom the silicon derivatives or their germanium homologues, the tantalumderivatives, lanthanide derivatives, or the magnesium derivatives ashereabove defined.
 5. The method of claim 3, wherein the metalcontaining dielectric film comprises a compound of the formula (I₄):(M¹ _(1-a)M² _(a))O_(b)N_(c)  (I₄) corresponding to the formula (I),wherein 0≦a<1 and 0<c≦0.5, wherein the M² metal containing precursor isselected from the silicon derivatives or their germanium homologues, thetantalum derivatives, lanthanide derivatives, or the magnesiumderivatives as hereabove defined, and at least one oxygen containingprecursor and at least one nitrogen containing precursor is introducedinto the reactor.
 6. The method of claim 3, wherein the siliconderivatives or their germanium homologues are selected from the groupconsisting of disiioxane, digermoxane, trisilylamine, trigermylamine,disilane, digermane, trisilane, trigermane, alkoxysilane having theformula Si H_(x)(OR³)_(4-x), and alkoxygermane having the formula GeH_(x)(OR³)_(4-x), wherein: 0≦x≦3 and R³ represents a linear or branchedhydrocarbon group having 1 to 6 carbon atoms.
 7. The method of claim 3,wherein the silanol derivative is Si(OH)(OtBu)₃.
 8. The method of claim3, wherein the aminosilane derivative is selected from the groupconsisting of tris(dimethylamino)silane [SiH(NMe₂)₃],bis(tertbutylamino)silane [SiH₂(NHtBu)₂], bis(diethylamino)silane[SiH₂(NEt₂)₂], and mixtures thereof.
 9. The method of claim 3, whereinthe aluminum derivative is selected from the group consisting oftrimethylaluminum [Al(CH₃)₃], dimethyl aluminum hydride [AlH(CH₃)₂], andalkoxyalane having the formula AlR⁸ _(x)(OR⁷)_(3-x), wherein 0≦x≦3, R⁷represents a linear or branched alkyl group having 1 to 6 carbon atom,and R⁸, identical to or different from R⁷, represents a hydrogen atom ora linear or branched alkyl group having 1 to 6 carbon atoms.
 10. Themethod of claim 9, wherein the aluminum derivative is AlMe₂(OiPr). 11.The method of claim 3, wherein the tantalum derivative is selected fromthe group consisting of Ta(OMe)₅; Ta(OEt)₅; Ta(NMe₂)₅; Ta(NEt₂)₅; atantalum derivative having the formulaTa(OR¹⁴)₄[O—C(R¹⁵)(R¹⁶)—CH₂—OR¹⁷], wherein R¹⁴, R¹⁵, R¹⁶ and R¹⁷,identical or different, independently represent a hydrogen atom or alinear or branched alkyl having 1 to 6 carbon atoms; a tantalumderivative having the formula Ta(OR¹⁸)₄[O—C(R¹⁹)(R²⁰)—CH₂—N(R²¹)(R²²)],wherein R¹⁸, R¹⁹, R²¹ and R²², identical or different, independentlyrepresent a hydrogen atom or a linear or branched alkyl having 1 to 6carbon atoms; and a tantalum derivative having the formulaTa(═NR²⁴)(NR²⁵R²⁶)₃, wherein R²⁴, R²⁵ and R²⁶, identical or different,independently represent an hydrogen atom or a linear or branched alkylhaving 1 to 6 carbon atoms.
 12. The method of claim 11, wherein thetantalum derivative is Ta(OEt)₄(OCMe₂CH₂—OMe).
 13. The method of claim3, wherein the niobium derivative is selected from the group consistingof Nb(OMe)₅; Nb(OEt)₅; Nb(NMe₂)₅; Nb(NEt₂)₄; Nb(NEt₂)₅; a niobiumderivative having the formula Nb(OR²⁷)₄(O—C(R²⁸)(R²⁹)—CH₂—OR³⁰), whereinR²⁷, R²⁸, R²⁹ and R³⁰, identical or different, independently represent ahydrogen atom or a linear or branched alkyl having 1 to 6 carbon atoms;a niobium derivative having the formulaNb(OR³¹)₄[O—C(R³²)(R³³)—CH₂—N(R³⁴)(R³⁵)], wherein R³¹, R³², R³³, R³⁴ andR³⁵, identical or different, independently represent a hydrogen atom ora linear or branched alkyl having 1 to 6 carbon atoms; and a niobiumderivative having the formula Nb(═NR³⁶)(NR³⁷R³⁸)₃, wherein R³⁶, R³⁷ andR³⁸, identical or different, independently represent an hydrogen atom ora linear or branched alkyl having 1 to 6 carbon atoms.
 14. The method ofclaim 13, wherein the niobium derivative is Nb(OEt)₄(OCMe₂CH₂—OMe). 15.The method of claim 3, wherein the M² metal containing precursor is ahafnium derivative.
 16. The method of claim 1, which further comprises:A step d), wherein the at least one M¹ metal containing precursor andoptionally the at least one M² metal containing precursor, is mixed toat least one reactant species prior to step c).
 17. The method of claim1, which further comprises: a step d′) wherein the at least one M¹ metalcontaining precursor and optionally the at least one M² metal containingprecursor, is mixed to at least one reactant species in the reactionchamber.
 18. The method of claim 1, wherein the metal containingdielectric film comprises a compound of the formula (I₁):M¹O₂  (I₁) corresponding to the formula (I), wherein a=0, b=2 and c=0.19. The method of claim 1, wherein the metal containing dielectric filmcomprises a compound of the formula (I₂):M¹O_(b)N_(c),  (I₂) corresponding to the formula (I), wherein a=0,1.5≦b≦2.5 and 0<c≦0.5.
 20. The method of claim 1, wherein the at leastone M¹ metal containing precursor is ZrCp(NMe₂)₃.
 21. The method ofclaim 1, wherein the at least one M¹ metal containing precursor isZr(MeCp)(NMe₂)₃.
 22. The method of claim 1, wherein the at least one Mmetal containing precursor is Zr(EtCp)(NMe₂)₃.